In the field of display technology, the display device is widely applied in the modem digital information apparatus due to its small volume, low power consumption, non-radiation and high resolution.
Generally, the display device comprises a display panel, wherein the display panel is formed by assembling two piece of display panel motherboards (such as an array substrate motherboard and a color film substrate motherboard), then cutting the assembled motherboards. The display panel motherboard is provided with cutting lines thereon, wherein the cutting lines is positioned on pre-cutting regions of the display panel motherboard. The display panel motherboard is divided into a plurality of display panels by the cutting lines, wherein the display panels are positioned on display panel regions of the display panel motherboard. After the display panel motherboard is cut according to the cutting lines, one display panel region corresponds to one display panel.
Generally, steps for forming the display panel motherboard comprise: forming a large area of films on a glass substrate, and making exposure and large area of etching, then forming structures of each layer of the display panel motherboard. Except for most portions of electrical insulating layers, other film layers are generally etched to form patterns (such as a gate line, a data line, a transparent electrode), and since the depositions of each electrical insulating layer (such as a gate insulating layer, a passivation layer) create different stress, resulting in the shrinking or expanding of the glass substrate.
For example, the passivation layer and the gate insulating layer are formed in large area film, and a few of via holes are formed finally. Therefore, after etching, the stress cannot be sufficiently released. After the passivation layer and the gate insulating layer are formed, the glass substrate is affected by the internal stress of large areas of electrical insulating layer, such as the passivation layer and the gate insulating layer), the intention of shrinking and expanding is not stable, which significantly affect subsequent procedures, especially, it may cause patterns of the film layers formed on the electrical insulating layers to offset.